The present invention relates to water-soluble chicory powder products and to processes and apparatus for producing such products.
The conventional processing of chicory comprises process steps of roasting, extraction and drying. The disadvantages of this processing are, on one hand, unevenness of the colour of the roast material and risk of burning chicory pieces and on the other hand, the hygroscopicity of the extract powders, and thus, water-soluble chicory powders currently on the market are not satisfactory with respect to sensory properties and because of excessive hygroscopicity.
In the conventional processing, the roasting is a process which is difficult to direct. The thermal decomposition of the carbohydrate, the pyrolysis of chicory inulin, proceeds exothermically. In the roaster, smaller chicory pieces are roasted more rapidly, and are therefore darker than the larger pieces, or are sometimes burnt. Larger chicory pieces are darker in the core than on the exterior. This uneven roasting has a disadvantageous effect on the flavour of the chicory extract. In addition, during the roasting and the extraction, the chicory inulin is cleaved to form fructose and glucose. The inulin cleavage must be kept within certain limits, so that the extract obtained is not excessively hygroscopic. Further, in order to be able to dry roast chicory extracts at all, in the spray-drying, the outlet air moisture, and thus the capacity of the towers, must be decreased. During the course of a relatively long operating time, encrustations occur in the tower which lead also to losses of material.